Air-jet spinners have a multiplicity of spinning positions. At every spinning position, a yarn is spun from an fiber structure. The fiber structure is first attenuated by reducing the amount of fiber per unit of length by a process called drafting. The attenuated fiber structure is then spun into a yarn at the spinning position by imparting twist. A spinning position includes a fiber guidance element with a fiber guiding surface. The fiber guidance element guides the fiber structure into a swirl chamber, where a yarn is produced in a spindle by the known vortex air-spinning process.
In FIG. 1 there is shown a fiber guidance element designed as a sleeve 3 with a fiber guiding surface 5 arranged inside. A fiber structure 1 is guided through the sleeve 3 from the pair of delivery rollers 2 of the upstream drafting system. High drafting system speeds lead to strong air flows in the region of the nip line of the delivery rollers. These air flows may lead to the breaking of the fiber structure. Due to the very high speeds at which the fiber structure is introduced from the drafting system into the spindle, the aim is to optimally design the entry of the fiber structure into the fiber guidance element located upstream of the spindle.
European Patent Application Publication No. EP 2 335 050 A2 proposes a sleeve in which two mutually inclined fiber guiding surfaces are arranged to form a deflecting location inside the sleeve. The deflecting location, formed as an edge, has the effect of lifting off the fiber ends and thereby increasing the proportion of free fiber ends on the surface of the fiber structure. These free fiber ends are taken up by the vortex flow before the spindle. Increasing the proportion of free fibers also has the effect of increasing the proportion of wrapping fibers of the yarn. As a result, the quality of a yarn spun in this way is improved. Although the deflecting location taught by EP 2 335 050 A2 improves the quality of the yarn, it does nothing to contribute to improving the flow conditions where the fiber structure 1 enters the fiber guidance element 3. When the fiber structure 1 enters the fiber guidance element 3, there is in particular the risk that the fibers lying parallel to the direction of introduction 34 will become jammed at edges that are necessarily present.
It is an object of the present invention to provide a spinning position with a fiber guidance element and to provide a fiber guidance element in which the flow conditions at the transition from the drafting system to the fiber guidance element are improved to achieve better conditions for the spinning of the fiber structure.